Radio transceiver



Jan. 27, 1948. M. TURKAT RADIO TRANSCEIVER' Filed Jan. 27, 1945 2Sheets-Sheet 1 :nanny unan U RN when...

Jal 27, l M. TURKT RADIO TRANSCEIVER Filed Jan.' 27, 1945 2 sheets-sheet2' 'INI/ENTOR. /V yf@ 77mm? Patented Jan. Z7, 1948 UNITED STATES PATENTOFFICE RADIO TRANSCEIVER Meyer Turkat, Brooklyn, N. Y.

Application January 27, 1945, Serial No. 574,907 8 Claims. (Cl. Z50- 13)This invention relates to new and useful improvements in a radiotransceiver.

More particularly, the invention proposes a new and improved radiotransceiver which is characterized by a receiver for broadcastreception, a transmitter for broadcasting, and an interceptor receiverfor switching oi said receiver and susbtituting itself in its place andsimultaneously switching on said transmitter. With this arrangement theradio transceiver may normally be receiving broadcast reception.However, when a transceiver sending station, to which the radiotransceiver is tuned, sends a message, the interceptor receiver willautomatically receive this message, by silencing the broadcast receptionwhich is being received` and substituting its message instead. It isonly necessary to talk into the microphone of the tranmitter to answerback the intercepting message, The invention contemplates the use of asuperheterodyne receiver for the broadcast reception. However it isfeasible to use a tuned radio frequency receiver, if this is desired.

The invention furthermore contemplates using the new radio transceiverwith a television receiver and a television broadcaster and with otherelectronic receivers such as frequency modulation, amplitude modulation,and phase modulatin sets. Thus meaning, it can be altered for thesevarious forms of reception,

Still further the invention proposes to use time relays which havecertain contact arms which clc-se instantly and which open with' delay,and which are arranged to keep the interceptor receiver and thetransmitter on through brief pauses. It is possible to set the timerelays so that the brief pauses may vary from a few seconds up tc a halfa minute, or more. With this arrangement the broadcast reception willnot cut back until the interceptor message is completed, even thoughthere is a short pause in the interceptor message.

The invention still further proposes to characterize the interceptorreceiver by the fact that it includes a radio frequency amplifierelectronic tube controlled by its antenna circuit, and controlling arelay tube which controls the time relay of the interceptor receiverwhich among other things connects said radio frequency amplifier tubewith the radio amplifier tube of the receiver for broadcast reception sothat the major portion of the receiver for broadcast then becomes aportion of the interceptor receiver and the intercepting message isheard over the loudspeaker which is used for the receiver for broadcastreception. It is furthermore proposed that the transmitter be providedwith amplifier electronic tubes controlled by the microphone circuit ofthe transmitter and controlling the time relay of the transmitter forreasons which will become clear as this specification proceeds.

The invention proposes to provide each of the time relays with a switchsection, and a coil section for controlling the switch section. Itisproposed that the switch sections do the necessary switching when thecoil sections are energized and deenergized.

The invention also contemplates that each 0f the time relays includestwo contact arms, one of which is used to control the coil of the relayand the other the time operation of the rst contact arm. v

Still further the invention proposes the con-'- struction of a radiotransceiver as briey described which will be reliable in action andwhich may be manufactured and sold at a relatively low cost. i

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appended claims in which thevarious novel features ofthe invention are more particularly set forth.

In the accompanying drawings forming amaterial part of this disclosure:

' Fig. 1 is a schematic diagram of a radio transceiver constructed inaccordance with this ine vention.

Fig. 2 isv a schematic diagram cfa radio transceiver constructed inaccordance with a modied form of this invention.

The radio transceiver, in accordance with that form of the inventiondisclosed in Fig. l, includes a superheterodyne receiver I 0 forbroadcast re-v ception, and having an antenna circuit Il which may betuned, a radio frequency amplifier tube l2 with the usual grid forconnection with said antenna circuit Il, and a conversion oscillatorill. The other details of the superheterodyne receiver will not be givenin this specification since they are not needed to understand theoperation of this invention, and their construction would be well knownby those skilled in the art. However, to facilitate al betterunderstanding of the invention some of the details ofthesuperhetgerodyne receiver have been schematically illus trated on thedrawing and will be readily recogniZed.

The superheterodyne receiver I0 is associated with an interceptorreceiver I6 having an antenna circuit I'I, a radio frequency amplifiertube I8 with the usual grid connected with the interceptor antennacircuit I'I, a relay control tube I9, in a time relay 2B controlled bysaid radio frequency tube I8, and a major portion of saidsuperheterodyne receiver II! including its loudspeaker. In other wordsthe interceptor receiver I6 and superheterodyne receiver I0 have someparts in common. The time relay 20 has double throw switch sections 2Iand 22. These switch sections 2l and 22 are normally closed in onedirection by energization of coils 'I9 and are capable of closing intotheir other, or second direction, or position when a message is comingover the antenna circuit I'I of said interceptor receiver I6, bydeenergization of the coils 'I9 and the action of springs 94 and 95. Theswitch sections 2| and 22 will close back to their normal positionsafter a short period of delay after said message is finished due to theaction of the time relay 20.

The radio .transceiver includes an electronic tube transmitter 25 havinga, microphone input relay section 26 and a remaining section 2l. Themicrophone input relay section 2t includes an amplifier tube 28, a relaycontrol tube 35 of a time relay 3I controlled by said amplier tube 23.This time relay 3i has a double throw switch section 32 normally closedin one direction by energication of coil 42 and closing into its seconddirection or position when a message is coming into said microphoneinput relay section 25 due to deener- `gization of the coil 42 and theaction of spring 96, and closing back to its normal position after ashort period of delay after said message is iinished due tovreenergization of the coil 42.

The interceptor relay switch section 2l has a contact arm Sii normallyconnecting the antenna circuit I I of said superheterodyne receiver Itwith the grid of the radio frequency amplifier I2 of saidsuperheterodyne receiver I5. When this con tact. arm 34 is in its otherdirection or position it connects the radio frequency tube I8 of saidinterceptor'receiver I6. with the grid of the radio frequency ampliertube I2. of .the superheterodynereceiver I0. The action of the contactarm 34 may be traced by noting that in its normal po.- sition, as.illustrated in Fig. l, it connects thev antenna circuit Il of thesuperheterodyne receiver IIJ with the grid of the radio frequencyamplifier tube I2. In its other direction, or position, that is itsSecond direction, or position, the contact arm Il!` will engage thecontact. 35.. Now the grid of the radio frequency amplifier tube I2 willbe controlled by the antenna circuit I'I of the intereeptor receiver I6.Said grid circuit includes a crystal selector 36 which allows its ownfrequency to pass but rejects all other frequencies. This represents axed waveV length., for theV operation of the interceptor receiverA I6.The crystal 36 is in the plate. circuit of tube. I8 and is` connectedwith said Contact 35.

At this'pointit may be best tol point out that. the drawings do, not.show all: of the circuits of the tubes of the transceiver, onlylthose'circuits which will; be generally understood by those. skilled inthe art.

The interceptor relay switch section 2 I has an.- other contact arm 38.which normally connects the. conversion oscillator I4 intof the circuitof said superheterodyne receiver I 0, and when this contact arm 36 is inits other direction. or position, it. disconnects said conversion.oscillator I from 'said superheterodyne receiver I0. This may beunderstood byy noting that the contact arm 3 3 in its normal' position,as illustrated on the drawing, connects the conversion oscillator I 4with the iirstdetector and mixer tube of the superheterodyne receiverI0. In its second position, the contact arm 38 will engage the contact39 which is a dead contact and which has no connection with anycircuits. For this reason the conversion oscillator I4 will bedisconnected from the superheterodyne receiver I0.

The switch section 22 of the interceptor relay 2li includes a contactarm d supplying when in its second position B plus voltage to themicrophone input relay section 26 of the transmitter 25. This contactarm I6 is illustrated in its first, or normal position. In this positionit is supplying B plus voltage from the power supply I to the coil 42 ofthe relay switch section 32. When the contact arm l0 is moved to itssecond position it will engage upon the contact 43 and then itwillsupply B plus voltage to the tubes 2S and 36 of the microphone inputsection 26.

The switch section 22 of the interceptor relay 20 is also provided withanother contact arm 46 for supplying filament voltage to the transmitter25 when in its second position. In its normal, or first position, asillustrated on the drawing, the contact arm 46 engages a dead contact4T. In its second position it will engage the contact d8 which willsupply filament voltage from the circuit 49 of the power supply 4I tothe various aments of the tubes contained in the transmitter 25. Thevarious tubes just referred to include the tubes 28 and 39 of themicrophone section 26 of the transmitter 25, as well as the tubes 50, 5Iand52 of the remaining section 21 of the transmitter 25. The tube 56 isthe usual modulator tube, 5I is the power amplier tube for supplying thenal plate output, and tube 52 is the master oscillator tube.

The switch section 32 of the transmitter relay 3l includes a contact arm5d for supplying B plus voltage to the remaining section 2'I of thetransmitter 25 when in its second position. In its normal, or firstposition, the contact arm 54 rests upon a dead contact 55. In thissecond position, it. will engage upon the contact 56. In this latterposition, the B plus voltage from the power supply 41 will now beconnected with the tubes 50, 5I and 52.

The switch section 32 of the transmitter relay also includes a contactarm 58 normally connecting the antenna of the antenna circuit I I withthe superheterodyne receiver IU, and when in its second direction, orposition connecting the antenna of the antenna circuit II with theoutput of the transmitter 25. The contact arm 58 is illustrated in itsnormal position, and in this position we may trace the antenna circuit II by starting at the antenna and following the lead through the contactarm 58 and back to the tuning parts of the antenna circuit I I. When thecontact arm 58 is. in its second position, it will rest upon a contact60. Now we may trace from the antenna of the antenna circuit I I throughthe arm 58 to the contact 6B and then to the output of the transmitter25. The output may be recognized by noting the nal plate output circuit6I from the tube 5I.

The time relay 26 includes a D. C. coil 65 which is connected in serieswith the screen circuit of the relay control tube I9. The coil 55normally attracts the contact arm 66 of the time relay 20. This contactarm 66 is urged away from the coil 65 and from the contact 'I1 by thespring 61. When the current passing through the coil 65 falls below apredetermined amount, the spring 61 will move the contact arm 66 on to acontact 68, The contact. 68 is connected with a contact ,13 of the-timerelay 28.v A contact arm 1I will rest on the contact when a message iscoming in through interceptor receiver I6 because the A. C. coil 14 willthen be highly energized. When the message ceases there will be a fallin current through coil 14 and then spring 12 will place contact arm 1Ionto contact 13, as illustrated on the drawing.

' The contact 18 is a dead contact. The coll 14 is connected in theplate circuit 15 of the relay control tube I9. The contact arm 1Icontrols the timer circuit 16. The timer circuit 16 includes a timeswitch T, for example such as the time switch disclosed in the U. S.Letters Patent No. 2,175,865, granted on October 10, 1939,

-to C. L. Anderson. Said time switch T is connected with the contact arm66 for locking the contact arm 66 on the contact 68 and for moving thecontact arm 66 01T the contact 68 and'back to its normal position onsaid contact 11. The time switch T is so adjusted (described in theAnderson patent) that the instant that the contact arm 1I engages thecontact 13 the timing operation starts provided that the contact arm 66is on contact 68, and should the contaotarm 1I leave the contact 13before the timing operation is completed, the time switch T will revertback to its rest or starting position. The only time that the timeswitch T will move the con- .tact arm 66 from the contact 68 to thecontact 11, will be when the contact arm 1I remains on the contact 13for a preselected period depending on the time setting of the switch T.

The contact 11 is connected in a circuit 18 which connects with thecoils 19 of the switch sections 2| and 22 of the time relay 20. The coil65 is so designed that when no message is coming in over the interceptorantenna circuit I1, the contact arm 66 will be kept upon the contact 11,due to a high energization of coil 65. However, as soon as a messagecornes in through the interceptor antenna circuit I1, there will be afall in current through the coil 65, and the spring 61 then moves thecontact arm 66 off the contact 11 and places it on the contact 68 andthe time switch T will hold it on contact 68 until released as justexplained.

The time relay 3| of the transmitter 25 includes a coil 84 which isconnected in the screen circuit of the relay control tube 30. This coil84 will attract the contact arm 85 when contact 40 engages contact 43and the natural delay of relay 3| expires and will maintain it upon thecontact 86 as long as no message is passing through the microphonecircuit 26. The spring 81 tends to place the contact arm 85 upon a,contact 88. This contact 88 is connected with a contact 89 which isengageable by a second contact arm 98. A spring 9|' maintains thecontact arm 90 on said contact 89. A coil 92 is connected with the platecircuit 93 of the relay control tube 30 and is capable of attracting thecontact arm 9 0 and placing it upon the dead contact 94. The contact arm90 is connected with a timingcircuit 9| which includes a time switch Tsuch as the switch shown by C. L. Anderson, supra. l This time switch Tis for the purpose of holding contact arm 85 on contact 86 and placingthe contact arm 85 back on the contact 86 after a delay period, as willbecome clearer during the explanation of the operation.

The switch section 2| is normally urged to its second position by saidspring 94. The switchsection 22 is normally urged to its second positionby said spring 95. The superheterodyne receiver '6 I0 has a loud speaker96 in a speaker housing 91. The microphone 98 of the transmitter 25 maybe mounted in the speaker housing 91 provided it is suitably shielded,so as not to be aiected by the radio broadcast coming from the loudspeaker 96 otherwise it may be mounted elsewhere. With this arrangementit is merely necessary to speak into the microphone 98 to transmit amessage.

The operation of the radio transceiver is as follows:

The superheterodyne receiver i8 is turned on in the usual way. This maybe done by the usual switch controlling the power supply 4I. When thepower supply 4I is turned on, the tubes I8 and I9 will also receivepower. The coil 65 will then attract the contact arm 66 and place it onthe contact 11. The coil 14 will place contact arm 1I on contact 10 whena message is received. The B plus from the power supply 4I is connectedthrough the contact arm 66, the contact 11, and the circuit 18 with thecoils 19 ofthe switch sections 2| and 22. The switch sections arethereupon moved to their normal positions, the positions illustrated onthe drawing. The contact arm 40 in its normal position supplies B plusvoltage to the coil 42 of the switch section 32 of the time relay of thetransmitter 25, which places the contact arms 54 and 58 into theirnormal, or first position, the position as illustrated. The receiver I8is now receiving broadcast reception. It may be tuned in the usual wayand its volume may be controlled as desired.

When a message is picked up by the interceptor circuit I1, and fed tothe grid of the radio frequency tube I9 there will be a drop of currentin the screen circuit of the tube which will cause a drop of current inthe coil 65. The spring 61 immediately moves the contact arm 66 from thecontact 11 and places it on the contact 68 where it is latched and heldby the time circuit 16. When the contact arm 66 moves oi the contact 11,the B plus voltage will be cut off from the circuit 18. The coils 19will become deenergized and the springs 94 and 95 will movethe contactarms 34, 38, 48 and 46, to their second positions. Simultaneously thereis an increase of current through the coil 14 and the coil will move thecontact arm 1I off of the contact 13 and place it on the contact 18. Itwill remain here as long as a message is coming over the interceptorantenna circuit I1. As soon as the message stops coming, the spring 12will move the contact arm 1I off of the contact 10 and place it back onthe contact 13. lit this time the contact arm 66 will still be on thecontact 68 and B plusV voltage will now be flowing through the contactarm 1I and through the circuit 16 and the time switch T. If a certainpreselected time period is now permitted to pass, the time switch T willmove the contact arm 66foi of the contact'68. andwill place itnback oncontact 11 which will then again connect the B plus'voltage tothe coils19 of the` relay switch sections 2| and 22 and the contact arms 34,38,-40 and 46 will be moved back to their normal positions.

When the contact arms 34, 38, 48 and 46 of the relays switch sections 2|and 22 assumed their second positi ons, the contactA 3.4 disconnectedthe superheterodyne antenna circuit II from the grid of the radiofrequency amplifier tube I2 and in its place connected the output oftube I8 as limited as to-its input frequency by'crystal 36to the grid ofthe V radiofrequency amplifier tube I2:

When 'the' contactarm 38' assumed its second position, it disconnectedthe conversion oscillator il from the-superheterodyne receiver I0.ln'the rst position of the contact arm 40, this contact arm 40 suppliedB plus voltage through the coil `42 of the switch section 32 of therelay 3l. When the contact arm 40 assumed its second position, upon thecontact 43, the contact arm 40 connected the B plus voltage with thetubes 28 and 3D of the microphone input relay section 26 of thetransmitter (25) and the contact arm 90 remained on the contact 89 andafter a short delay the contact arm 85 assumes a position on contact 86.The contact arm 46 turned on the filament current to all of thefilaments of the tubes in the transmitter (25), when it assumed itssecond position on the contact 48. The interceptor message is now comingin over the superheterodyne receiver l and may be heard through the loudspeaker 96, and the transmitter is ready to broadcast an answer.

The person receiving the interceptor message may respond by merelytalking into the microphone 98. This will immediately aiect the tubes 28and 30. The relay control tube 3i) will respond accordingly. It willcause a drop in current, going through the coil 84. The spring 8i thenmoves the contact arm 85 onto the contact 88 and an increase of currentin coil 92 places contact arm 9i) upon the dead contact 94. When thecontact arm 85 leaves the contact 86, the B plus voltage through theswitch coil 42 is cut, so that the spring 8B is free to move the contactarms 54 and 5S to their second positions. The contact arm 54 will thenconnect the B plus voltage to the tubes 50, I and 52. The contact arm 58will connect the antenna of the superheterodyne receiver l0 of theoutput circuit 62 of the transmitter 25.

' The signal voltage from the plate circuit of the relay control tube 30will energize the coil $2 which flips the contact arm 90 to the deadcontact S4 as long as the transmitter 25 is broadcasting. As soon as themessage ceases to go over the transmitter 25 the coil 92 will thenreduce in signal current so that the spring 9 I places the contact armSii on the contact 89. At this time the contact arm 85 is still on thecontact 88 and B plus voltage will be supplied to the circuit 3lcontrolling the timing switch T. After a predetermined time, the switchT will operate to move the contact arm 85 back upon the contact 85.However, should the broadcaster again talk into the microphone58,*before the expiration of the time interval, as timed by the timeswitch T the contact arm Si! will leave contact 89 and the time switch Twill revert to its rest or starting position. The time interval willstart repeating when the contact arm S5 re-engages the con# tact 8S.When the interceptor message coming over the antenna circuit Il' stops,the interceptor receiver i6- will revert back to its original positionafter a. time interval as controlled by the time switch 'I'.'in relay2l). This causes the' superheterodyne receiver I5 to revert back toreceive the broadcast reception.

In Fig. 2 a modified form of the invention has been disclosed which isidentical to the prior Iorm distinguishing merely in the fact that twoadditional tubes |00 and ll have been vadded to the interceptor receiverso that the interceptor receiver can be adjusted or designed to receiveany frequency desired.. 'The tube IUI is a, conversion oscillator, whilethe tube 100 is -a 8 detector and mixer tube. These tubes are conn'ectedwith the contact 35 so that the contact arm 34 may connect theinterceptor receiver with the grid of the radio frequency amplifier tubel2 of the superheterodyne receiver IU.

In other respects this form of the invention is identical to the priorform and like parts may be recognized by the same reference'numerals.

While I have illustrated and described the preferred embodimnts of myinvention, it isto be understood that I do not limit myself to theprecise constructions herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdened in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by United States Letters Patent is:

l. In a radio receiving and transmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of differentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching off said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultanously switching offsaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connectingsaid interceptor receiver with said control tube for iniiuencing theoutput of said tube, an output circuit for said control tube forcontrolling said relay, a time switch in said output circuit forarresting operation of said relay for preset periods each time itswitches said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of said presetperiods responsive to reception of an incoming message of saidinterceptor receiver.

. 2. In a radio receiving and transmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of differentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a, relay having a. switch section connected with saidbroadcast receiver and transmitter for switching oli said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultaneously switching offsaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connectingsaid interceptor receiver with said control tube for influencing theoutput of said tube, an' output circuit for said control tube forcontrolling sald relay, a time switch in said output circuit forarresting operation of said relay for preset periods each time itswitches said broadcast receiver oi and said transmitteron, and meansfor resetting said time switch before A the expiration of said presetperiods responsivel to reception of an incoming message of saidinterceptor receiver, said power supply to saidrelay being controlledwith a contact arm, said time switch arresting operation of said contactarm for arresting operation of said relay.

' -3. In a radio receiving and transmitting device, a receiver forbroadcast' reception adapted to be tuned to receive a number ofdifferent wave lengths, an interceptor receiver tuned to a certain wavelength, a transmitter, a relay having a switch section connected withsaid broadcast receiver and transmitter for switching off said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultaneously switching offsaid transmitter, a power supply for said relay,l a control tube forsaid relay, a power supply for said control tube, an input circuitconnecting said interceptor receiver with said control tube forinuencing the output of said tube, an output circuit for said controltube for controlling said relay, a time switch in said output circuitfor arresting operation of said relay for preset periods each time itswitches said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of said presetperiods responsive to reception of an incoming message of saidinterceptor receiver, said power supply to said relay being controlledwith a contact arm, said time switch arresting operation of said contactarm for arresting operation of said relay, said contact arm beingresiliently urged in one direction, and electromagnetic means responsiveto said output circuit for urging said contact arm in the otherdirection for making or breaking said power supply to said relay.

4. In a radio receiving and transmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of diierentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching off said broadcastreceiver and simultaneously switching on said transmitter and forswitchingv on said broadcast receiver and simultaneously switching 01Tsaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connectingsaid interceptor receiver with said control tube for iniiuencing theoutput of said tube, an input circuit for said control tube forcontrolling said relay, a time switch in said output circuit forarresting operation of said relay for preset periods each time itswitches said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of said presetperiods responsive to reception of an in-A coming message of saidinterceptor receiver, including a time switch circuit for controllingsaid time switch, a contact arm for controlling said time switchcircuit, resilient means urging said contact arm in one direction, andelectromagnetic means responsive to said output circuit for urging saidcontact arm in the other direction for making or breaking said timeswitch circuit.

5. In a radio receiving and transmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of differentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching off said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultaneously switching ofisaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connect-ving said interceptor receiver with said control tube for influencing theoutput of said tube, an output circuit for said control tube forcontrolling said relay, a time switch in said output circuit forarresting operation of said relay for preset periods each time itswitches said broadcast rel0 ceiver oi and said transmitter on, andmeans for resetting said time switch before the expiration of saidpreset periods responsive to reception of an incoming message of saidinterceptor receiver, said transmitter having a microphone input sectionand a remaining section, and switch section acting to turn on and oir"said microphone input section, a relay having a switch section connectedwith said remainingv section for switching it on and oi, a power supplyfor said second named relay, a control tube for said second named relay,a power supply for said second named control tube, an input circuitconnecting said microphone input section with said second named controltube for influencing the output of said second named tube, an output'circuit for said second named tube for controlling said second namedrelay, a time switch in said second named output circuit for arrestingoperation of said second named relay for preset periods each time itswitches on said remaining section, and means for resetting said secondnamed time switch before the expiration of its said preset periodsresponsive to a message on said microphone inputsection.

6. In a radio receiving and vtransmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of differentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching oir said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultaneously switching oisaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connectingsaid interceptor receiver with said control tube for influencing theoutput of said tube, an output circuit for said control tube forcontrolling said relay, a time switch in said output circuit forarresting operation of said relay for preset periods each time itswitches'said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of saidA presetperiods responsive to reception of an incoming message of saidinterceptor receiver, said transmitter having a microphone input sectionand a remaining section, and switch section acting to turn on and offsaid microphone input section, a relay having a switch section connectedwith said remaining section for switching it 'on and off, a power supplyfor said second named relay, a control tube for said second namedrelay,v

a power supply for said second named control tube, an input circuitconnecting said microphone input section with said second named controltube for inuencing the output of said second named tube, an outputcircuit for said second named tube for controlling said second namedrelay, a time switch in said second named output circuit for arrestingoperation of said second named relay for preset periods each time itswitches on said remaining section, and means for resetting said secondnamed time switch before the expiration of its said preset periodsresponsive to a message on said microphone input section, said powersupply to said second named relay being controlled with a lcontact arm,said second named time switch arresting operation of said second namedcontact arm for arresting operation of said second named relay.

7. In a radio receiving and transmitting device, a receiver forbroadcast reception adapted to be tuned to receive a number of dierentwave lengths, an interceptor receiver tuned to a certain wave, length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching oi said broadcastreceiver and simultaneously switching on said transmitter and forswitching on said broadcast receiver and simultaneously switching oisaid transmitter, a power supply for said relay, a control tube for saidrelay, a power supply for said control tube, an input circuit connectingsaid interceptor receiver with said control tube for influencing theoutput of said tube, an output circuit for said control tube forcontrolling said relay, a time switch in said output circuit -forarresting operation of said relay for preset periods each time itswitches said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of said presetperiods responsive toreception of an incoming message of saidinterceptor receiver, said transmitter having a microphone input sectionand a remaining section, and switch section acting to turn on and oisaid microphone input section, a relay having a switch section connectedwith said remaining section for switching it on and ofi, a power supplyfor said second named relay, a control tube for said second named relay,a power supply for said second named control tube, an input circuitlconnecting said microphone input section with said second named controltube for influencing the output of said second named tube, an outputcircuit for said second named tube for controlling said second namedrelay, a time switch in said second named output circuit for arrestingoperation of said second named relay for preset periods each time itswitches on said remaining section, and means for resetting said secondnamed time switch before the expiration of its second preset periodsresponsive to a message on said microphone input section, said powersupply to said second named relay being controlled with a `contact arm,said second named time switch arresting operation of said second namedcontact arm for arresting operation of said second named relay, saidsecond named contact arm being resiliently urged in one direction, andelectromagnetic means responsive to said second named output circuit formaking or breaking said power supply to said second named relay.

8. In a radio receiving and transmitting device, a` receiver forbroadcast reception adapted to be tuned to receive a number of differentwave lengths, an interceptor receiver tuned to a certain wave length, atransmitter, a relay having a switch section connected with saidbroadcast receiver and transmitter for switching off said broadcastreceiver and simultaneously switching 1-2 on said transmitter and forswitching on said broadcast receiver and simultaneously switching olsaid transmitter,- a power supply for said relay, a control tube forsaid relay, a power supply for said control tube, an input circuitconnecting said interceptor receiver with said control tube forinfluencing the output of said tube, an output circuit for said controltube for controlling said relay, a time switch in said output circuitfor arresting operation of said relay for preset periods each time itswitches said broadcast receiver off and said transmitter on, and meansfor resetting said time switch before the expiration of said presetperiods responsive to reception of an incoming message of saidinterceptor receiver, said transmitter having a microphone input sectionand a remaining section, and switch section acting to turn onV and onsaid microphone input section, a relay having a switch section connectedwith said remaining section forswitchng it on and ol, a power supply forsaid second named relay, a control tube for said second named relay, apowerrsupply for said second named control tube, an input circuitconnecting said microphone input section with said second named controltube for iniiuencing the output of said second named tube, an outputcircuit for said second named tube for controlling said second namedrelay, a time switch in' said second named output circuit for arrestingoperation of said second named relay for preset periods each time itswitches on said remaining section, and means for resetting said secondnamed time switch before the expiration of its said preset Periodsresponsive to a message on said microphone input section, including atime switch circuit for controllng said second named time switch, acontact arm for controlling said time switch circuit, resilient meansurging said contact arm in one direction, and electromagnetic meansresponsive to said second named output circuit for urging said contactarm in the other direction for making or breaking said time switchcircuit.

TURKAT.

REFERENCES CITED The following references are of record in the file ofthis patent:

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